398 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			398 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Generic EP93xx GPIO handling
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|  *
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|  * Copyright (c) 2008 Ryan Mallon
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|  * Copyright (c) 2011 H Hartley Sweeten <hsweeten@visionengravers.com>
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|  *
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|  * Based on code originally from:
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|  *  linux/arch/arm/mach-ep93xx/core.c
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|  *
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|  *  This program is free software; you can redistribute it and/or modify
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|  *  it under the terms of the GNU General Public License version 2 as
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|  *  published by the Free Software Foundation.
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|  */
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| 
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| #include <linux/init.h>
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| #include <linux/module.h>
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| #include <linux/platform_device.h>
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| #include <linux/io.h>
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| #include <linux/irq.h>
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| #include <linux/slab.h>
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| #include <linux/gpio/driver.h>
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| /* FIXME: this is here for gpio_to_irq() - get rid of this! */
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| #include <linux/gpio.h>
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| 
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| #include <mach/hardware.h>
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| #include <mach/gpio-ep93xx.h>
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| 
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| #define irq_to_gpio(irq)	((irq) - gpio_to_irq(0))
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| 
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| struct ep93xx_gpio {
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| 	void __iomem		*mmio_base;
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| 	struct gpio_chip	gc[8];
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| };
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| 
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| /*************************************************************************
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|  * Interrupt handling for EP93xx on-chip GPIOs
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|  *************************************************************************/
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| static unsigned char gpio_int_unmasked[3];
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| static unsigned char gpio_int_enabled[3];
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| static unsigned char gpio_int_type1[3];
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| static unsigned char gpio_int_type2[3];
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| static unsigned char gpio_int_debounce[3];
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| 
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| /* Port ordering is: A B F */
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| static const u8 int_type1_register_offset[3]	= { 0x90, 0xac, 0x4c };
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| static const u8 int_type2_register_offset[3]	= { 0x94, 0xb0, 0x50 };
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| static const u8 eoi_register_offset[3]		= { 0x98, 0xb4, 0x54 };
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| static const u8 int_en_register_offset[3]	= { 0x9c, 0xb8, 0x58 };
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| static const u8 int_debounce_register_offset[3]	= { 0xa8, 0xc4, 0x64 };
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| 
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| static void ep93xx_gpio_update_int_params(unsigned port)
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| {
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| 	BUG_ON(port > 2);
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| 
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| 	writeb_relaxed(0, EP93XX_GPIO_REG(int_en_register_offset[port]));
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| 
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| 	writeb_relaxed(gpio_int_type2[port],
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| 		EP93XX_GPIO_REG(int_type2_register_offset[port]));
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| 
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| 	writeb_relaxed(gpio_int_type1[port],
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| 		EP93XX_GPIO_REG(int_type1_register_offset[port]));
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| 
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| 	writeb(gpio_int_unmasked[port] & gpio_int_enabled[port],
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| 		EP93XX_GPIO_REG(int_en_register_offset[port]));
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| }
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| 
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| static void ep93xx_gpio_int_debounce(unsigned int irq, bool enable)
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| {
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| 	int line = irq_to_gpio(irq);
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| 	int port = line >> 3;
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| 	int port_mask = 1 << (line & 7);
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| 
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| 	if (enable)
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| 		gpio_int_debounce[port] |= port_mask;
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| 	else
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| 		gpio_int_debounce[port] &= ~port_mask;
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| 
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| 	writeb(gpio_int_debounce[port],
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| 		EP93XX_GPIO_REG(int_debounce_register_offset[port]));
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| }
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| 
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| static void ep93xx_gpio_ab_irq_handler(struct irq_desc *desc)
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| {
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| 	unsigned char status;
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| 	int i;
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| 
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| 	status = readb(EP93XX_GPIO_A_INT_STATUS);
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| 	for (i = 0; i < 8; i++) {
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| 		if (status & (1 << i)) {
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| 			int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_A(0)) + i;
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| 			generic_handle_irq(gpio_irq);
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| 		}
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| 	}
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| 
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| 	status = readb(EP93XX_GPIO_B_INT_STATUS);
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| 	for (i = 0; i < 8; i++) {
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| 		if (status & (1 << i)) {
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| 			int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_B(0)) + i;
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| 			generic_handle_irq(gpio_irq);
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| 		}
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| 	}
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| }
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| 
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| static void ep93xx_gpio_f_irq_handler(struct irq_desc *desc)
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| {
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| 	/*
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| 	 * map discontiguous hw irq range to continuous sw irq range:
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| 	 *
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| 	 *  IRQ_EP93XX_GPIO{0..7}MUX -> gpio_to_irq(EP93XX_GPIO_LINE_F({0..7})
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| 	 */
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| 	unsigned int irq = irq_desc_get_irq(desc);
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| 	int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */
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| 	int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_F(0)) + port_f_idx;
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| 
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| 	generic_handle_irq(gpio_irq);
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| }
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| 
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| static void ep93xx_gpio_irq_ack(struct irq_data *d)
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| {
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| 	int line = irq_to_gpio(d->irq);
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| 	int port = line >> 3;
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| 	int port_mask = 1 << (line & 7);
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| 
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| 	if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) {
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| 		gpio_int_type2[port] ^= port_mask; /* switch edge direction */
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| 		ep93xx_gpio_update_int_params(port);
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| 	}
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| 
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| 	writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
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| }
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| 
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| static void ep93xx_gpio_irq_mask_ack(struct irq_data *d)
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| {
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| 	int line = irq_to_gpio(d->irq);
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| 	int port = line >> 3;
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| 	int port_mask = 1 << (line & 7);
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| 
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| 	if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH)
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| 		gpio_int_type2[port] ^= port_mask; /* switch edge direction */
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| 
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| 	gpio_int_unmasked[port] &= ~port_mask;
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| 	ep93xx_gpio_update_int_params(port);
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| 
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| 	writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
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| }
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| 
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| static void ep93xx_gpio_irq_mask(struct irq_data *d)
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| {
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| 	int line = irq_to_gpio(d->irq);
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| 	int port = line >> 3;
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| 
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| 	gpio_int_unmasked[port] &= ~(1 << (line & 7));
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| 	ep93xx_gpio_update_int_params(port);
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| }
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| 
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| static void ep93xx_gpio_irq_unmask(struct irq_data *d)
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| {
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| 	int line = irq_to_gpio(d->irq);
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| 	int port = line >> 3;
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| 
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| 	gpio_int_unmasked[port] |= 1 << (line & 7);
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| 	ep93xx_gpio_update_int_params(port);
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| }
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| 
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| /*
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|  * gpio_int_type1 controls whether the interrupt is level (0) or
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|  * edge (1) triggered, while gpio_int_type2 controls whether it
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|  * triggers on low/falling (0) or high/rising (1).
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|  */
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| static int ep93xx_gpio_irq_type(struct irq_data *d, unsigned int type)
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| {
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| 	const int gpio = irq_to_gpio(d->irq);
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| 	const int port = gpio >> 3;
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| 	const int port_mask = 1 << (gpio & 7);
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| 	irq_flow_handler_t handler;
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| 
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| 	gpio_direction_input(gpio);
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| 
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| 	switch (type) {
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| 	case IRQ_TYPE_EDGE_RISING:
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| 		gpio_int_type1[port] |= port_mask;
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| 		gpio_int_type2[port] |= port_mask;
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| 		handler = handle_edge_irq;
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| 		break;
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| 	case IRQ_TYPE_EDGE_FALLING:
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| 		gpio_int_type1[port] |= port_mask;
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| 		gpio_int_type2[port] &= ~port_mask;
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| 		handler = handle_edge_irq;
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| 		break;
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| 	case IRQ_TYPE_LEVEL_HIGH:
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| 		gpio_int_type1[port] &= ~port_mask;
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| 		gpio_int_type2[port] |= port_mask;
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| 		handler = handle_level_irq;
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| 		break;
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| 	case IRQ_TYPE_LEVEL_LOW:
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| 		gpio_int_type1[port] &= ~port_mask;
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| 		gpio_int_type2[port] &= ~port_mask;
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| 		handler = handle_level_irq;
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| 		break;
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| 	case IRQ_TYPE_EDGE_BOTH:
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| 		gpio_int_type1[port] |= port_mask;
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| 		/* set initial polarity based on current input level */
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| 		if (gpio_get_value(gpio))
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| 			gpio_int_type2[port] &= ~port_mask; /* falling */
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| 		else
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| 			gpio_int_type2[port] |= port_mask; /* rising */
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| 		handler = handle_edge_irq;
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| 		break;
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| 	default:
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| 		return -EINVAL;
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| 	}
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| 
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| 	irq_set_handler_locked(d, handler);
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| 
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| 	gpio_int_enabled[port] |= port_mask;
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| 
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| 	ep93xx_gpio_update_int_params(port);
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| 
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| 	return 0;
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| }
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| 
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| static struct irq_chip ep93xx_gpio_irq_chip = {
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| 	.name		= "GPIO",
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| 	.irq_ack	= ep93xx_gpio_irq_ack,
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| 	.irq_mask_ack	= ep93xx_gpio_irq_mask_ack,
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| 	.irq_mask	= ep93xx_gpio_irq_mask,
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| 	.irq_unmask	= ep93xx_gpio_irq_unmask,
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| 	.irq_set_type	= ep93xx_gpio_irq_type,
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| };
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| 
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| static void ep93xx_gpio_init_irq(void)
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| {
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| 	int gpio_irq;
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| 
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| 	for (gpio_irq = gpio_to_irq(0);
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| 	     gpio_irq <= gpio_to_irq(EP93XX_GPIO_LINE_MAX_IRQ); ++gpio_irq) {
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| 		irq_set_chip_and_handler(gpio_irq, &ep93xx_gpio_irq_chip,
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| 					 handle_level_irq);
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| 		irq_clear_status_flags(gpio_irq, IRQ_NOREQUEST);
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| 	}
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| 
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| 	irq_set_chained_handler(IRQ_EP93XX_GPIO_AB,
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| 				ep93xx_gpio_ab_irq_handler);
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| 	irq_set_chained_handler(IRQ_EP93XX_GPIO0MUX,
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| 				ep93xx_gpio_f_irq_handler);
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| 	irq_set_chained_handler(IRQ_EP93XX_GPIO1MUX,
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| 				ep93xx_gpio_f_irq_handler);
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| 	irq_set_chained_handler(IRQ_EP93XX_GPIO2MUX,
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| 				ep93xx_gpio_f_irq_handler);
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| 	irq_set_chained_handler(IRQ_EP93XX_GPIO3MUX,
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| 				ep93xx_gpio_f_irq_handler);
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| 	irq_set_chained_handler(IRQ_EP93XX_GPIO4MUX,
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| 				ep93xx_gpio_f_irq_handler);
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| 	irq_set_chained_handler(IRQ_EP93XX_GPIO5MUX,
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| 				ep93xx_gpio_f_irq_handler);
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| 	irq_set_chained_handler(IRQ_EP93XX_GPIO6MUX,
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| 				ep93xx_gpio_f_irq_handler);
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| 	irq_set_chained_handler(IRQ_EP93XX_GPIO7MUX,
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| 				ep93xx_gpio_f_irq_handler);
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| }
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| 
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| 
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| /*************************************************************************
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|  * gpiolib interface for EP93xx on-chip GPIOs
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|  *************************************************************************/
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| struct ep93xx_gpio_bank {
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| 	const char	*label;
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| 	int		data;
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| 	int		dir;
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| 	int		base;
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| 	bool		has_debounce;
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| };
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| 
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| #define EP93XX_GPIO_BANK(_label, _data, _dir, _base, _debounce)	\
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| 	{							\
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| 		.label		= _label,			\
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| 		.data		= _data,			\
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| 		.dir		= _dir,				\
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| 		.base		= _base,			\
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| 		.has_debounce	= _debounce,			\
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| 	}
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| 
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| static struct ep93xx_gpio_bank ep93xx_gpio_banks[] = {
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| 	EP93XX_GPIO_BANK("A", 0x00, 0x10, 0, true),
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| 	EP93XX_GPIO_BANK("B", 0x04, 0x14, 8, true),
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| 	EP93XX_GPIO_BANK("C", 0x08, 0x18, 40, false),
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| 	EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24, false),
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| 	EP93XX_GPIO_BANK("E", 0x20, 0x24, 32, false),
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| 	EP93XX_GPIO_BANK("F", 0x30, 0x34, 16, true),
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| 	EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48, false),
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| 	EP93XX_GPIO_BANK("H", 0x40, 0x44, 56, false),
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| };
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| 
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| static int ep93xx_gpio_set_config(struct gpio_chip *chip, unsigned offset,
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| 				  unsigned long config)
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| {
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| 	int gpio = chip->base + offset;
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| 	int irq = gpio_to_irq(gpio);
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| 	u32 debounce;
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| 
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| 	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
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| 		return -ENOTSUPP;
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| 
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| 	if (irq < 0)
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| 		return -EINVAL;
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| 
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| 	debounce = pinconf_to_config_argument(config);
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| 	ep93xx_gpio_int_debounce(irq, debounce ? true : false);
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| 
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| 	return 0;
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| }
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| 
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| /*
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|  * Map GPIO A0..A7  (0..7)  to irq 64..71,
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|  *          B0..B7  (7..15) to irq 72..79, and
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|  *          F0..F7 (16..24) to irq 80..87.
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|  */
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| static int ep93xx_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
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| {
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| 	int gpio = chip->base + offset;
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| 
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| 	if (gpio > EP93XX_GPIO_LINE_MAX_IRQ)
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| 		return -EINVAL;
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| 
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| 	return 64 + gpio;
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| }
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| 
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| static int ep93xx_gpio_add_bank(struct gpio_chip *gc, struct device *dev,
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| 	void __iomem *mmio_base, struct ep93xx_gpio_bank *bank)
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| {
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| 	void __iomem *data = mmio_base + bank->data;
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| 	void __iomem *dir =  mmio_base + bank->dir;
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| 	int err;
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| 
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| 	err = bgpio_init(gc, dev, 1, data, NULL, NULL, dir, NULL, 0);
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| 	if (err)
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| 		return err;
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| 
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| 	gc->label = bank->label;
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| 	gc->base = bank->base;
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| 
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| 	if (bank->has_debounce) {
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| 		gc->set_config = ep93xx_gpio_set_config;
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| 		gc->to_irq = ep93xx_gpio_to_irq;
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| 	}
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| 
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| 	return devm_gpiochip_add_data(dev, gc, NULL);
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| }
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| 
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| static int ep93xx_gpio_probe(struct platform_device *pdev)
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| {
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| 	struct ep93xx_gpio *ep93xx_gpio;
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| 	struct resource *res;
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| 	int i;
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| 	struct device *dev = &pdev->dev;
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| 
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| 	ep93xx_gpio = devm_kzalloc(dev, sizeof(struct ep93xx_gpio), GFP_KERNEL);
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| 	if (!ep93xx_gpio)
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| 		return -ENOMEM;
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| 
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| 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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| 	ep93xx_gpio->mmio_base = devm_ioremap_resource(dev, res);
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| 	if (IS_ERR(ep93xx_gpio->mmio_base))
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| 		return PTR_ERR(ep93xx_gpio->mmio_base);
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| 
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| 	for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
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| 		struct gpio_chip *gc = &ep93xx_gpio->gc[i];
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| 		struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i];
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| 
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| 		if (ep93xx_gpio_add_bank(gc, &pdev->dev,
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| 					 ep93xx_gpio->mmio_base, bank))
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| 			dev_warn(&pdev->dev, "Unable to add gpio bank %s\n",
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| 				bank->label);
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| 	}
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| 
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| 	ep93xx_gpio_init_irq();
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| 
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| 	return 0;
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| }
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| 
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| static struct platform_driver ep93xx_gpio_driver = {
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| 	.driver		= {
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| 		.name	= "gpio-ep93xx",
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| 	},
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| 	.probe		= ep93xx_gpio_probe,
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| };
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| 
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| static int __init ep93xx_gpio_init(void)
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| {
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| 	return platform_driver_register(&ep93xx_gpio_driver);
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| }
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| postcore_initcall(ep93xx_gpio_init);
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| 
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| MODULE_AUTHOR("Ryan Mallon <ryan@bluewatersys.com> "
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| 		"H Hartley Sweeten <hsweeten@visionengravers.com>");
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| MODULE_DESCRIPTION("EP93XX GPIO driver");
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| MODULE_LICENSE("GPL");
 | 
